// script.aculo.us slider.js v1.8.1, Thu Jan 03 22:07:12 -0500 2008

// Copyright (c) 2005-2007 Marty Haught, Thomas Fuchs 
//
// script.aculo.us is freely distributable under the terms of an MIT-style license.
// For details, see the script.aculo.us web site: http://script.aculo.us/

if (!Control) var Control = { };

// options:
//  axis: 'vertical', or 'horizontal' (default)
//
// callbacks:
//  onChange(value)
//  onSlide(value)
Control.Slider = Class.create({
	initialize: function( handle, track, options )
	{
		var slider = this;

		if (Object.isArray(handle))
		{
			this.handles = handle.collect(function( e )
			{
				return $(e)
			});
		}
		else
		{
			this.handles = [$(handle)];
		}

		this.track = $(track);
		this.options = options || { };

		this.axis = this.options.axis || 'horizontal';
		this.increment = this.options.increment || 1;
		this.step = parseInt(this.options.step || '1');
		this.range = this.options.range || $R(0, 1);

		this.value = 0; // assure backwards compat
		this.values = this.handles.map(function()
		{
			return 0
		});
		this.spans = this.options.spans ? this.options.spans.map(function( s )
		{
			return $(s)
		}) : false;
		this.options.startSpan = $(this.options.startSpan || null);
		this.options.endSpan = $(this.options.endSpan || null);

		this.restricted = this.options.restricted || false;

		this.maximum = this.options.maximum || this.range.end;
		this.minimum = this.options.minimum || this.range.start;

    // Will be used to align the handle onto the track, if necessary
		this.alignX = parseInt(this.options.alignX || '0');
		this.alignY = parseInt(this.options.alignY || '0');

		this.trackLength = this.maximumOffset() - this.minimumOffset();

		this.handleLength = this.isVertical() ?
							(this.handles[0].offsetHeight != 0 ?
							 this.handles[0].offsetHeight : this.handles[0].style.height.replace(/px$/, "")) :
							(this.handles[0].offsetWidth != 0 ? this.handles[0].offsetWidth :
							 this.handles[0].style.width.replace(/px$/, ""));

		this.active = false;
		this.dragging = false;
		this.disabled = false;

		if (this.options.disabled) this.setDisabled();

    // Allowed values array
		this.allowedValues = this.options.values ? this.options.values.sortBy(Prototype.K) : false;
		if (this.allowedValues)
		{
			this.minimum = this.allowedValues.min();
			this.maximum = this.allowedValues.max();
		}

		this.eventMouseDown = this.startDrag.bindAsEventListener(this);
		this.eventMouseUp = this.endDrag.bindAsEventListener(this);
		this.eventMouseMove = this.update.bindAsEventListener(this);

    // Initialize handles in reverse (make sure first handle is active)
		this.handles.each(function( h, i )
		{
			i = slider.handles.length - 1 - i;
			slider.setValue(parseFloat(
					(Object.isArray(slider.options.sliderValue) ?
					 slider.options.sliderValue[i] : slider.options.sliderValue) ||
					slider.range.start), i);
			h.makePositioned().observe("mousedown", slider.eventMouseDown);
		});

		this.track.observe("mousedown", this.eventMouseDown);
		document.observe("mouseup", this.eventMouseUp);
		document.observe("mousemove", this.eventMouseMove);

		this.initialized = true;
	},
	dispose: function()
	{
		var slider = this;
		Event.stopObserving(this.track, "mousedown", this.eventMouseDown);
		Event.stopObserving(document, "mouseup", this.eventMouseUp);
		Event.stopObserving(document, "mousemove", this.eventMouseMove);
		this.handles.each(function( h )
		{
			Event.stopObserving(h, "mousedown", slider.eventMouseDown);
		});
	},
	setDisabled: function()
	{
		this.disabled = true;
	},
	setEnabled: function()
	{
		this.disabled = false;
	},
	getNearestValue: function( value )
	{
		if (this.allowedValues)
		{
			if (value >= this.allowedValues.max()) return(this.allowedValues.max());
			if (value <= this.allowedValues.min()) return(this.allowedValues.min());

			var offset = Math.abs(this.allowedValues[0] - value);
			var newValue = this.allowedValues[0];
			this.allowedValues.each(function( v )
			{
				var currentOffset = Math.abs(v - value);
				if (currentOffset <= offset)
				{
					newValue = v;
					offset = currentOffset;
				}
			});
			return newValue;
		}
		if (value > this.range.end) return this.range.end;
		if (value < this.range.start) return this.range.start;
		return value;
	},
	setValue: function( sliderValue, handleIdx )
	{
		if (!this.active)
		{
			this.activeHandleIdx = handleIdx || 0;
			this.activeHandle = this.handles[this.activeHandleIdx];
			this.updateStyles();
		}
		handleIdx = handleIdx || this.activeHandleIdx || 0;
		if (this.initialized && this.restricted)
		{
			if ((handleIdx > 0) && (sliderValue < this.values[handleIdx - 1]))
				sliderValue = this.values[handleIdx - 1];
			if ((handleIdx < (this.handles.length - 1)) && (sliderValue > this.values[handleIdx + 1]))
				sliderValue = this.values[handleIdx + 1];
		}
		sliderValue = this.getNearestValue(sliderValue);
		this.values[handleIdx] = sliderValue;
		this.value = this.values[0]; // assure backwards compat

		this.handles[handleIdx].style[this.isVertical() ? 'top' : 'left'] =
		this.translateToPx(sliderValue);

		this.drawSpans();
		if (!this.dragging || !this.event) this.updateFinished();
	},
	setValueBy: function( delta, handleIdx )
	{
		this.setValue(this.values[handleIdx || this.activeHandleIdx || 0] + delta,
				handleIdx || this.activeHandleIdx || 0);
	},
	translateToPx: function( value )
	{
		return Math.round(
				((this.trackLength - this.handleLength) / (this.range.end - this.range.start)) *
				(value - this.range.start)) + "px";
	},
	translateToValue: function( offset )
	{
		return ((offset / (this.trackLength - this.handleLength) *
				 (this.range.end - this.range.start)) + this.range.start);
	},
	getRange: function( range )
	{
		var v = this.values.sortBy(Prototype.K);
		range = range || 0;
		return $R(v[range], v[range + 1]);
	},
	minimumOffset: function()
	{
		return(this.isVertical() ? this.alignY : this.alignX);
	},
	maximumOffset: function()
	{
		return(this.isVertical() ?
			   (this.track.offsetHeight != 0 ? this.track.offsetHeight :
				this.track.style.height.replace(/px$/, "")) - this.alignY :
			   (this.track.offsetWidth != 0 ? this.track.offsetWidth :
				this.track.style.width.replace(/px$/, "")) - this.alignX);
	},
	isVertical:  function()
	{
		return (this.axis == 'vertical');
	},
	drawSpans: function()
	{
		var slider = this;
		if (this.spans)
			$R(0, this.spans.length - 1).each(function( r )
			{
				slider.setSpan(slider.spans[r], slider.getRange(r))
			});
		if (this.options.startSpan)
			this.setSpan(this.options.startSpan,
					$R(0, this.values.length > 1 ? this.getRange(0).min() : this.value));
		if (this.options.endSpan)
			this.setSpan(this.options.endSpan,
					$R(this.values.length > 1 ? this.getRange(this.spans.length - 1).max() : this.value, this.maximum));
	},
	setSpan: function( span, range )
	{
		if (this.isVertical())
		{
			span.style.top = this.translateToPx(range.start);
			span.style.height = this.translateToPx(range.end - range.start + this.range.start);
		}
		else
		{
			span.style.left = this.translateToPx(range.start);
			span.style.width = this.translateToPx(range.end - range.start + this.range.start);
		}
	},
	updateStyles: function()
	{
		this.handles.each(function( h )
		{
			Element.removeClassName(h, 'selected')
		});
		Element.addClassName(this.activeHandle, 'selected');
	},
	startDrag: function( event )
	{
		if (Event.isLeftClick(event))
		{
			if (!this.disabled)
			{
				this.active = true;

				var handle = Event.element(event);
				var pointer = [Event.pointerX(event), Event.pointerY(event)];
				var track = handle;
				if (track == this.track)
				{
					var offsets = Position.cumulativeOffset(this.track);
					this.event = event;
					this.setValue(this.translateToValue(
							(this.isVertical() ? pointer[1] - offsets[1] : pointer[0] - offsets[0]) - (this.handleLength / 2)
							));
					var offsets = Position.cumulativeOffset(this.activeHandle);
					this.offsetX = (pointer[0] - offsets[0]);
					this.offsetY = (pointer[1] - offsets[1]);
				}
				else
				{
					// find the handle (prevents issues with Safari)
					while ((this.handles.indexOf(handle) == -1) && handle.parentNode)
						handle = handle.parentNode;

					if (this.handles.indexOf(handle) != -1)
					{
						this.activeHandle = handle;
						this.activeHandleIdx = this.handles.indexOf(this.activeHandle);
						this.updateStyles();

						var offsets = Position.cumulativeOffset(this.activeHandle);
						this.offsetX = (pointer[0] - offsets[0]);
						this.offsetY = (pointer[1] - offsets[1]);
					}
				}
			}
			Event.stop(event);
		}
	},
	update: function( event )
	{
		if (this.active)
		{
			if (!this.dragging) this.dragging = true;
			this.draw(event);
			if (Prototype.Browser.WebKit) window.scrollBy(0, 0);
			Event.stop(event);
		}
	},
	draw: function( event )
	{
		var pointer = [Event.pointerX(event), Event.pointerY(event)];
		var offsets = Position.cumulativeOffset(this.track);
		pointer[0] -= this.offsetX + offsets[0];
		pointer[1] -= this.offsetY + offsets[1];
		this.event = event;
		this.setValue(this.translateToValue(this.isVertical() ? pointer[1] : pointer[0]));
		if (this.initialized && this.options.onSlide)
			this.options.onSlide(this.values.length > 1 ? this.values : this.value, this);
	},
	endDrag: function( event )
	{
		if (this.active && this.dragging)
		{
			this.finishDrag(event, true);
			Event.stop(event);
		}
		this.active = false;
		this.dragging = false;
	},
	finishDrag: function( event, success )
	{
		this.active = false;
		this.dragging = false;
		this.updateFinished();
	},
	updateFinished: function()
	{
		if (this.initialized && this.options.onChange)
			this.options.onChange(this.values.length > 1 ? this.values : this.value, this);
		this.event = null;
	}
});
